05 PT overheats when idle

[sponge9012]

hey everyone. hope someone can give me some help with this issue.

my 05 pt (65,000 miles) has begun to overheat, but only when its sitting. it cools right back down if you drive it.

it also leaked a bit of coolant that i saw. this was before it was overheating that i saw the leak. and when i took it to a shop, they pressure tested it and found no leaks. also said fan was working. suggested a radiator cap. obviously that didnt work or i wouldnt be here so overflow for some reason maybe? havent seen any (leaks) since, but it wasnt much to begin with. just happened to look under the car and saw a droplet.

someone told me thermostat, but would that cause it to do this? im thinking (from the reading ive been doing) that its maybe the high speed fan relay instead? they said the fan was working, but would they check the relays?

im a little hesitant to do the thermostat myself.

i also had the fan replaced less than a year ago, because my car was shaking when the ac switched on. even though the fan would switch on, it wasnt working right i guess. i dont know. i do know that the new fan fixed the shaking.

anyway, any input is appreciated.

[allhale09]

Well if the thermostat was bad it could be stuck closed and causing a backup in your system causing a leak somewhere.

[sponge9012]

that makes sense, but would i only get the problem when i was at a stop? i would think it would be more of a problem if it was the thermostat. but i mean, thats why im here asking.

[allhale09]

Well when you're at idle air isnt passing through the radiator cooling the coolant.When you're driving air passes through the radiator cooling the liquid inside.I'm no expert but thats just what it seems like.My 85' Chevy C10 had that same problem so I bought a new thermostat and it fixed the problem.

[sponge9012]

ill repost after the thermostat is replaced. i guess no reason to put off a possible $10 solution . . .

i know i read something about the relay for the high speed going bad, anybody have experience with this?

[CREWZIN]

Sorry, not the relay going bad, the high speed part of the fan goes bad. When the engine heats up the fan kicks into high speed by means of a temperature sensor, relay and PCM. Of all the over-heatings we've had on the forum (and there has been loads of them including mine) the fan motor was bad in 95% of them. A couple thermostats, head gaskets, trapped air in the system but I can't remember anyone changing the relay and fixing their problem.

[sponge9012]

in this case, it would be spectacular if it was the fan, because its still under warranty from the last time i replaced it! it sure wasnt fun last time.

so if it is the fan, and not the thermostat, this would be 3 times for the fan. (first was for a front end collision) but no tsb or recall? this is crazy. thats hundreds of dollars for that fan . . .

[CREWZIN]

The thing is to test it before buying a new one. I believe a scanner can turn the two speeds on but it will cost to have someone hook it up. If your handy, you can get under the car, unhook the electrical connection to the fan and attach hot and ground wires to the wires leading to the fan motor to see if both speeds work. You can also swap the high speed relay with the horn relay in the fuse box under the hood because they are both the same. There's no way to check out the PCM without that scan tool. Anyway, here's how it all works.

[sponge9012]

took it in today, indeed it is the fan.

so the last one i put in lasted less than a year. and the one before that lasted less than 2 years.

this is a really expensive factory part, whats the deal? why so much trouble for it to keep working?

even under the warranty i still have to pay labor, roughly 130. should i just start putting aside money for a new fan every year?

[CREWZIN]

I changed mine back in 2002 so it's been going for almost 7 years. I had to get it from a dealer in Texas as there was a National Back-order for them....what's that tell you about how many of them were burning out. $130 ain't bad. I've heard from members on this forum of some dealers charging around $400 for labor only.

I'll add you to the "bad fan motor" part of the equation and bump it up to 96% percent of over-heating problems.